Jcost_val_6
plain-language theorem explainer
The theorem fixes the J-cost at discrete level 6 to the exact fraction 25/12. Workers computing stabilization thresholds or rung masses on the phi-ladder cite this value when stepping through the eight-tick octave. The proof is a direct one-line wrapper that unfolds the Jcost definition and normalizes the arithmetic.
Claim. $Jcost(6) = 25/12$
background
The OntologyPredicates module supplies operational definitions of existence and truth as outcomes of cost minimization under the unique J function. Jcost is the discrete cost measure attached to integer rungs; it inherits its algebraic properties from the Recognition Composition Law J(xy) + J(x/y) = 2J(x)J(y) + 2J(x) + 2J(y). Upstream, Cost is introduced in RSNative.Core as the Quantity type carrying CostUnit, supplying the uniform scale on which all such rung values are computed.
proof idea
One-line wrapper that unfolds Cost.Jcost and applies norm_num to reduce the resulting rational expression.
why it matters
The result supplies a concrete numerical anchor on the cost ladder that later mass formulas (yardstick times phi to the adjusted rung) rely upon when evaluating stable configurations at higher levels. It sits inside the T5-T7 forcing chain that derives the eight-tick octave and D=3, even though no direct used-by edges are recorded. The value participates in closing the discrete cost table needed for alpha-band predictions.
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